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Finding the Fourth Proportional to 310.85, 465.87 and 128.15

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Solution

The fourth proportional to 310.85, 465.87 and 128.15 is: 192.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.85 : 465.87 = 128.15 : x
  2. Step 2: Convert to fraction form
    310.85/465.87 = 128.15/x
  3. Step 3: Cross multiply
    310.85x = 465.87 × 128.15
  4. Step 4: Simplify right side
    310.85x = 59,698.91
  5. Step 5: Solve for x
    x = 59,698.91/310.85
  6. Step 6: Final answer
    x = 192.05

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.